JPH0451297A - musical tone synthesizer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a musical tone synthesis device for synthesizing tones similar to those of an acoustic musical instrument, that is, a natural musical instrument, in particular.

[Conventional technology]

In recent years, digital sound synthesis methods have been introduced to electronic musical instruments, and the quality of synthesized sounds has improved significantly. Input methods have also become more diverse, including keyboards, wind instrument shapes, and guitar shapes. There is. As a musical tone synthesis method, the musical sound waveform of a natural instrument is memorized as it is,
A so-called PC that plays at a speed proportional to the pitch to be played.
Although many methods based on the M method are used, many tone synthesis methods have also been proposed that correspond to the actual pronunciation forms of natural musical instruments.

Such functionality is described, for example, in the literature (“On the
cillation of musical instruments
ruments + M, E.

McIntyre R,T, 5chusacher
Co-authored by J, Woodhouse, J, Acoust,
Sac, Am 74 (5) + November 1
983, pages 1325-1345).

The above-mentioned musical tone synthesis device will be described below with reference to the drawings.

FIG. 8 shows the configuration of a conventional musical tone synthesis device.

Before explaining FIG. 8, the principle will be explained with reference to FIGS. 5 to 7.

FIG. 5 shows a cross-sectional view of the clarinet. In FIG. 5, it is assumed that the left end A corresponds to the mouthpiece, and its lead portion is covered by the mouth having an oral cavity pressure q. It is assumed that all tone holes are closed.Due to the pressure difference between the 0 oral cavity pressure q and the pipe pressure q just below the reed, an airflow with a flow velocity f is generated near the reed. The airflow at the flow rate f forms a traveling wave pressure qo (-fz) via the characteristic impedance 2 inside the pipe. The traveling wave pressure q0 is from the left end A to the right end B (open end) in Fig. 5.
The zero reflected wave pressure q8 at which radiation and reflection occur at the right end B after traveling to the right end B can be obtained by convolving the traveling wave pressure q0 and the reflection coefficient r(t) as shown in Fig. 7. I can do it. The reflected wave pressure q, which travels inside the pipe from the right end B to the left end A, is the pressure inside the pipe directly below the lead, q.
(=q.

+ql) changes, a flow velocity r determined from the oral cavity pressure q and the intraductal pressure q is generated in the vicinity of the reed from the relationship shown in FIG. By repeating these actions, the clarinet's sound will be repeated.

Since the clarinet is a quarter-wavelength tube, the reflection coefficient r (t) in Figure 7 is the time period of the output pitch T.
Then, it can be seen that the peak of reflection is concentrated at the time length T/2 corresponding to the round trip path 21 from the right end B to the left end A due to the reflection from the left end A to the right end B and further at the right end B. .

FIG. 6 shows the relationship between the pipe internal pressure q just below the lead and the flow velocity f. Note that ql corresponds to the pressure required to overcome the restoring force of the reed and close the gap between the reed and the mouthpiece.

In FIG. 8, 120 is a driving section, 121 is a converting section, 1
22 is a delay section, and 123 is a key-on processing section.

The operation of the musical tone synthesis apparatus configured as described above will be explained below.

First, a note signal J indicating the pitch of the musical tone to be output, a cow-on signal a indicating the timing of sound generation, and a touch signal S indicating the intensity of the output musical tone are input to the musical tone synthesizer. Then, the key-on processing section 123 outputs a reset signal C to the delay section 122 in response to the turning on of the key-on signal a, and after a predetermined period of time has elapsed, the key-on processing section 123 outputs a reset signal C to the delay section 122. An on signal d is output to each section of the converting section 121 and the delay section 122, and the operation of each section is started. The driving unit 120 outputs data q, which is initial touch when the musical tone to be output is a percussive sound such as a piano, or aftertouch when the musical tone is a non-percussive sound such as a clarinet, and the on signal d output from the key-on processing unit 123. It outputs while it is on, and when the on signal d is off, it outputs a zero value.

The data q may be scaled to an appropriate value as the output of the drive unit.

The conversion unit 121 is configured as shown in FIG. 9, for example. In FIG. 9, 130 is the F (q) table;
1 is a multiplier, and 132 and 133 are adders.

In the conversion unit 121 configured as described above, the traveling wave pressure q0 output immediately before and the reflected wave pressure q8 output from the delay unit 122 are added by the adder 133, and the pipe internal pressure q just below the lead becomes F( q) Output to table 130. The F (q) table 130 outputs the flow velocity f corresponding to the input pipe pressure q according to the relationship shown in FIG. The flow rate r output from the F(q) table 130
is multiplied by characteristic impedance 2 of the pipe in a multiplier 131, and then reflected wave pressure q in an adder 132.

is added and output as the traveling wave pressure q0.

The delay section 122 is configured as shown in FIG. 10, for example. In FIG. 1O, 160 is a reflection coefficient generating section;
1 to 163 are unit delays, 171 to 174 are multipliers, 1
65 is an accumulator.

The delay unit 122 zero-resets the unit delays 161 to 163 according to the reset signal C output from the key-on processing unit 123, and on the other hand, the reflection coefficient generation unit 160
is the reference clock Cf(
It is assumed that the reflection coefficient r(i-Cf) obtained by sampling every Sec:l is calculated based on equation (1) and then supplied to each of the multipliers 171 to 174.

However, i=0.1, 2. ..., 2N.

r(i-cf) = AIExp (-B(i-cf
-T)) = (1) (]) In the formula, A and B are constants determined by the assumed reflection characteristics of the tube. N is the number of unit delays shown in 161-163, and is a positive integer that is 1 less than the number of multipliers 171-174. Here, if the lowest tone output by the clarinet is, for example, 100 [Hz] and the frequency of the reference clock Cf is 20 (KHz), then the number N of unit delay devices is (2) in the case of a quarter wavelength tube. It can be determined as in Eq.

N=(1/2) −(1/100(Hz)) −2
0000 (Hz) = 100
...(2) In the delay section 122, the coefficient control for forming the pitch corresponding to the note signal J is performed as follows:
In the reflection coefficient generating section 160, after calculating and generating rN-Cf) obtained by equation (1) in correspondence with each note signal J, that is, the time period T of each pitch, these are sent to multipliers 171 to 174. will be supplied.

When the key-on processing section 123 outputs the on signal d, the delay section 122 starts calculating the reflected wave pressure q with respect to the traveling wave pressure q0 output from the conversion section 121.

As described above, the traveling wave pressure q0 output from the terminal 180 in FIG.
The reflected wave pressure q output from the converter 81 is output as an input to the converter 121.

Note that in order to quickly output the digital musical tone output from the terminal 180 in FIG. 10, it may be output from the terminal 185.

Furthermore, musical tones are synthesized for other musical instruments such as violin strings and pipe organs by the same operation as for the clarinet described above.

[8B to be Solved by the Invention] However, according to the above-mentioned conventional configuration, there is a problem in that the musical tone output is delayed because musical tone synthesis is started after the sounding of the reflection coefficient is instructed. .

Furthermore, even though it is possible to reproduce the oscillation (sound production) mechanism unique to each acoustic instrument, it is difficult to synthesize high-quality musical tones.For example, in the case of the clarinet mentioned above, , the sound that is synthesized when changing the pitch is the sound that is created by changing the length of the clarinet tube.For example, a note one octave higher is played on a clarinet with half the tube length (from the mouthpiece to the bell). This has the problem that it becomes equivalent to

Furthermore, there is a problem in that complicated calculations are required to generate the reflection coefficient.

SUMMARY OF THE INVENTION An object of the present invention is to provide a musical tone synthesis device that can solve the above-mentioned conventional problems and easily synthesize high-pitched tones of natural musical instruments with high quality.

[Means for Solving the Problems] A musical tone synthesis device of the present invention includes a conversion section, a filter, a memory, and a reflection coefficient supply section.

The converter outputs a traveling wave component from the drive input to the musical instrument and the reflected wave component.

The filter calculates and outputs a reflected wave component with respect to a traveling wave component.

The memory is configured to store a plurality of reflection coefficient sets corresponding to each pitch, each consisting of a plurality of reflection coefficients for calculating reflected wave components.

The reflection coefficient supply section reads out a reflection coefficient set corresponding to the output pitch instruction from the memory and supplies it to the filter.

[Function] According to the configuration of the present invention, the reflection characteristics of the musical instrument that vary depending on the pitch of the musical tone are stored in advance as a reflection coefficient set in the memory, so that the
When synthesizing a musical tone while calculating and generating a traveling wave component and a reflected wave component, the reflection coefficient supply section can read a corresponding reflection coefficient set from the memory and supply it to the filter according to the input pitch instruction. . Then, in the filter, a reflected wave component is calculated using a reflection coefficient set supplied from the reflection coefficient supply section for the traveling wave component output from the conversion section.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a block diagram of a musical tone synthesizer according to an embodiment of the present invention.

In FIG. 1, 220 is a delay section, and 201 is a memory. Note that 120 is a drive section, 121 is a conversion section, and 123 is a key-on processing section, which have the same configuration as the conventional example.

FIG. 2 shows a block diagram of the delay section 220 and memory 201 in FIG. 1.

In FIG. 2, 200 is a reflection coefficient supply section, and 202 is a filter. In addition, 161 to 163 are unit delay devices, 1
71 to 174 are multipliers, and 165 is an accumulator, which have the same structure as the conventional example.

Wind instruments such as the clarinet and flute generally control the pitch by changing the length of the tube, but at the same time the shape of the tube also changes, which causes the timbre of the musical sound to differ depending on the pitch. For example, when all the keys on a clarinet are pressed, a musical tone with a fundamental tone that makes the entire length of the tube equal one-fourth of the wavelength is output, but when there are keys that are not pressed, that is, there are openings. Sometimes, for example, a fundamental musical tone with a quarter wavelength from the reed to the aperture is output, but the timbre is also affected by the shape from the aperture to the bell.

In this example, an impulse is generated at the mouthpiece of a wind instrument, the response obtained for each fingering of each pitch (-J) of the instrument is measured at the mouthpiece, and this impulse response rj (1) is sampled in the same manner as in the conventional example, and stored as is in the memory 201 as a reflection coefficient set. Note that the number of reflection coefficients for each reflection coefficient section is at least equal to the number K of reflection coefficients in the reflection coefficient set necessary for synthesizing the lowest tone of the instrument to be output. Here, the number of reflection coefficients required to synthesize the lowest note has a relationship as shown in equation (3) based on the pitch FL [Hz] of the lowest note and the reference clock Cf [5ec].

K≧=1/(FL-Cf)...(3)
In equation (3), k is the word length of one period of the lowest tone when the sampling period is the reference clock Cf, and since the reflection coefficients are distributed around k, it is desirable that the number of reflection coefficients be about 2. .

The reflection coefficient supply unit 200 receives a note signal J (J=1.2
．． ..., 32) is input, the storage start address ADR3O (=
Since the reflection coefficients for words are read from J- to -K (Word) and the corresponding reflection coefficients are sent to K multipliers 171 to 174, the reflected waves with different characteristics for each note signal J are generated. The pressure q is calculated and output.

Below, the reflection coefficient supply section 200 will be explained in FIGS. 2 to 4.
This will be explained with reference to the figures.

FIG. 3 shows a block diagram of the reflection coefficient supply section 200 in FIG. 2.

In FIG. 3, 250 to 252 are registers, 253 is a switch, 254 is an inverter, 255 is an AND circuit,
256 is a multiplier, 257 to 260 are adders, 261 to 2
63 is a latch.

Incidentally, FIG. 4 shows a timing chart of each part of the reflection coefficient supply section 200.

Each part of the reflection coefficient supply section 200 is configured by an AND circuit 25 determined from the reference clock Cr and the zero flag of the register 252.
It is assumed that the operation is performed at a timing that is an integral multiple of the clock output from 5.

First, when the reset signal C is output from the key-on processing unit 123, the address data ADR5O calculated from the input note signal J by the adder 257 and the multiplier 256 as described above is initially stored in the register 250. Set. At the same time, the registers 251 and 252 are initialized to O and (K=1), respectively. Additionally, the latches 261 to 263 are also initialized to O. Memory 201 outputs reflection coefficient DATAO corresponding to address data ADR3O output from register 250. The switch 253 sends the reflection coefficient DATAO to the 0th latch 261 according to the value “0” indicated by the contents of the register 251, and the content “DATAO” of the latch 261 is sent to the 0th multiplier 171 of the filter 202. Used as a multiplier value. At this time, the other multipliers 172 to 174 in the filter 202 do not function as valid operations because the contents of the latches 262 to 263 are "0".

Next, when the key-on processing unit 123 outputs the on signal d according to the timing of the reference clock cf, the registers 250 and 251 each increase by 1 and become ADRS1 and 1 according to the clock CLI, and
The register 252 is decremented by 1 to become (K-2). Through the same operation as described above, the address AD of the memory 201 is
The reflection coefficient DATAI stored in R3I is now sent to the latch 262, and the contents of the latch 262 “DATA
I'' is used as the effective multiplier value in the first multiplier 172 of filter 202.

Repeating the above operations, ADRS (
When DATA (K-1) stored in DATA (K-1) comes to be used as a valid multiplication value in the (K-1)th multiplier 174 of the filter 202, the value of the register 252 becomes O and the zero flag is set. is output, AND circuit 2
Since the clock is no longer output from 55, the reflection coefficient supply unit 200 ends its reflection coefficient supply operation.

As described above, the reflection coefficient supply unit 200 sequentially sends out reflection coefficients in the order necessary for calculation, according to the timing based on the reference clock Cf.

The driving section 120, the converting section 121, the key-on processing section 123, the unit delay units 161 to 163 of the delay section 220, and the multipliers 171 to 174 perform musical tone synthesis corresponding to the reference clock Cf by operations similar to conventional ones. Therefore, terminal 1
From 90 onwards, the traveling wave pressure q0 is output as a musical tone that is influenced by reflected waves that vary depending on the pitch. By the way, if a digital musical tone is output from the terminal 195, sound generation can be started with a delay of only one reference clock Cf after the key-on signal a is turned on. Also,
The reflected wave pressure q output from the terminal 191 is the converter 1
It will be output as an input to 21.

In this embodiment, an example of a wind instrument has been explained, but the same applies to other instruments such as stringed instruments and percussion instruments. This can be constructed by storing the impulse response r,(1) reflected at the driving point in the memory 201 as a reflection coefficient set corresponding to the pitch.

As described above, according to this embodiment, corresponding to each pitch,
Since the reflection coefficient cents having different reflection characteristics are read out from the memory 201 in the same way as an actual musical instrument, high-quality musical tones can be synthesized by using the filter 202 with an appropriate number of stages for each instrument without calculating the reflection coefficient set. becomes possible.

Furthermore, in this embodiment, since the filter 202 is configured as an acyclic filter, even if the reflection coefficients are sent one by one to the filter 202 at each timing corresponding to the reference clock Cf, the calculation timing in the filter 202 will be affected. Musical tone synthesis becomes possible without causing any problems.

〔Effect of the invention〕

The musical tone synthesis device of the present invention stores the reflection characteristics of the musical instrument, which differ depending on the pitch of the musical tone, as a reflection coefficient set in the memory in advance, so that the forward wave component and the reflected wave component are When synthesizing a musical tone while calculating and generating, the filter simply calculates the reflected wave component using the reflection coefficient set read from the memory corresponding to the pitch of the output musical tone supplied from the reflection coefficient supply section.
It is possible to easily create tones similar to those of natural instruments.

Furthermore, since there is no need to calculate the reflection coefficient cent, the time delay in the start of sound generation relative to the sound generation instruction can be made very small.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a musical tone synthesizer according to an embodiment of the present invention, FIG. 2 is a block diagram showing the structure of the delay section and memory in FIG. 1, and FIG. 3 is a block diagram of the reflection coefficient supply section in FIG. 2. A block diagram showing the configuration, FIG. 4 is an operation timing diagram of the reflection coefficient supply section in FIG.
FIG. 7 is a reflection coefficient characteristic diagram, FIG. 8 is a block diagram of a conventional musical tone synthesizer, and FIGS. 9 and 10 are block diagrams of various parts in the conventional example. 121... Conversion unit, 200... Reflection coefficient supply unit, 2
01...Memory, 202...Filter, 220...
・Delay part -) -〇~, Q culm], O Fig. Fig. Fig. Fig.

Claims (1)

[Scope of Claims] A conversion unit that outputs a traveling wave component from a drive input to a musical instrument and a reflected wave component; a filter that calculates and outputs the reflected wave component for the traveling wave component; and a filter that calculates and outputs the reflected wave component from the traveling wave component; a memory that stores a plurality of reflection coefficient sets corresponding to each pitch made up of a plurality of reflection coefficients for calculation; and a reflection coefficient that reads out the reflection coefficient set corresponding to an output pitch instruction from the memory and supplies it to the filter. A musical tone synthesis device comprising a supply section.